1. Field of the Invention
The present invention relates to imaging, and more specifically, it relates to the use of ultrasound for tomographic imaging.
2. Description of Related Art
The ultrasound imaging has many advantages over ionizing radiation, especially, for example, in breast examinations. Employing acoustics to produce breast images, especially full three-dimensional reconstructions, while preserving the overall morphology and indicating various internal structures and regions such as ducts, epithelial tissue, masses, lesions, etc. is extremely powerful in detecting various carcinomas. Ultrasonic imaging has been used to image lumps in the body since there is a clear difference between a cyst and a suspected cancerous tumor. Recent research has demonstrated the potential for ultrasonic imaging to differentiate cancerous from non-cancerous lesions in the breast.
An aspect of the present invention includes a system and method comprising a first element designed to transmit first sound waves and receive first sound wave echoes; and a second element designed to receive second sound waves from said first element.
Another aspect of the present invention includes a system and method comprising recording ultrasonic tomographic transmission mode sound speed data and attenuation data to produce sound speed projection data and attenuation projection data; reconstructing said sound speed projection data and attenuation projection data using a straight ray approximation to produce a first reconstruction of a sound speed image and a first reconstruction of an attenuation image; and iteratively correcting said first reconstruction of said sound speed image and the first reconstruction of said attenuation image using a bent ray backprojection technique.
Another aspect of the present invention includes a method and system comprising recording reflection mode images of a target at a plurality of projection angles; calculating an error weighting factor; applying said error weighting factor to the reflection mode images; calculating impedance values at each angle to obtained weighted impedance images; and calculating density of the target from the plurality of projection angles.